Abaixo está uma instrução que descreve uma tarefa de geração de SQL, combinada com uma entrada que fornece mais contexto sobre os esquemas de tabela disponíveis. Escreva o código SQL que responda adequadamente à solicitação
 ###Instrução: Que tipo de jogo 3D a Valve Corporation lançou?
 ###Tabelas: CREATE TABLE free_play (free_play_id AUTO_INCREMENT PRIMARY KEY, Developer(s) VARCHAR, Release date VARCHAR, Required OS VARCHAR, Genre VARCHAR, Type VARCHAR) CREATE TABLE afl_draftees (afl_draftees_id AUTO_INCREMENT PRIMARY KEY, Draft VARCHAR, Pick INT, Player VARCHAR, Club VARCHAR, Games INT, Goals INT) CREATE TABLE winners_of_the_virginia_derby_since_1998 (winners_of_the_virginia_derby_since_1998_id AUTO_INCREMENT PRIMARY KEY, Year INT, Winner VARCHAR, Jockey VARCHAR, Trainer VARCHAR, Owner VARCHAR, Distance (Miles) VARCHAR, Time VARCHAR) CREATE TABLE summary_of_results (summary_of_results_id AUTO_INCREMENT PRIMARY KEY, Party VARCHAR, Burnley INT, Chorley INT, Fylde INT, Hyndburn INT, Lancaster INT, Pendle INT, Preston INT, Ribble Valley INT, Rossendale INT, South Ribble INT, West Lancashire INT, Wyre INT, Total INT) CREATE TABLE player_list (player_list_id AUTO_INCREMENT PRIMARY KEY, Player VARCHAR, AFL debut VARCHAR, Games VARCHAR, Goals VARCHAR, Behinds VARCHAR, Kicks VARCHAR, Handballs VARCHAR, Disposals VARCHAR, Marks VARCHAR, Tackles VARCHAR)  
SELECT Genre FROM free_play WHERE Type = 3d AND Developer(s) = valve corporation